Avalanche forecast

Sea To Sky

Dec 11 – 12, 2012Avalanche Canada
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Archived · expired 14 years ago

Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–5
    Expect to encounter touchy wind slabs below ridge crests, behind terrain features, and in cross-loaded gullies. Be especially diligent as northerly winds start to reverse load unusual aspects.

Confidence

Fair - Due to limited field observations for the entire period

Weather Forecast

Wednesday: Partly cloudy with no significant precipitation expected, freezing levels dropping as low as sea level, and light northerly winds increasing throughout the day. Thursday: Increasing cloud throughout the day with snow starting in the afternoon, freezing levels rising as high as 700m and moderate westerly  winds becoming strong southwesterlies with the onset of precipitation. Friday: Snow easing throughout the day with 20-25cm total since Thursday, moderate westerly winds and freezing levels hovering around 700m.

Avalanche Summary

Reports from yesterday include isolated pockets of thin wind slabs reactive to ski cuts producing relatively harmless avalanches, but expect wind slabs to have since gotten deeper and more reactive. Loose surface snow is also sluffing readily on steep slopes.

Snowpack Summary

Expect to find pockets of touchy wind slabs in exposed areas. Sheltered areas have 20-30cm of light unconsolidated snow above a gradually stiffening snowpack. Snowpack tests have not been showing any consistent results in the recent storm snow. The early November crust may be buried between 100-200cm down depending on the total depth of the snowpack in your area. Although unlikely, avalanches associated with this crust could be massive. It may also be a bigger problem where it has a layer of facetted crystals above, rather than where it is like a laminated sandwich of crusts and facets. If that sounds too technical for you, then the take home is that this is not an easy problem to gauge when or where it might wake up.

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